Self-retracting type seat belt device for vehicle use

ABSTRACT

A self-retracting type seat belt device which is adapted to keep an appropriate slack in the seat belt applied around the user&#39;&#39;s body. The seat belt comprises a buckle including one buckle member movable on the vehicle body and normally biased to assume an extended position. The buckle member is temporarily retracted to lock the belt winder under the engaging pressure of the other buckle member secured to the free end of the seat belt when the belt is buckled up.

11] 3,750,102 [4 1 July 31, 1973 United States Patent [1 1 Okada3,712,401 l/1973 Rothschild 180/82 C SELF-RETRACTING TYPE SEAT BELTDEVICE FOR VEHICLE USE FOREIGN PATENTS OR APPLlCATlONS 9/1960Australia...........................

[73] Assignee:

Primary Examiner-Alvin H. Waring AttorneyEric H. Waters et al.

[22]- Filed:

[21] Appl. No.: 260,732

[57] ABSTRACT A self-retracting type seat belt device which is adapted[30] Foreign Application Priority Data June 9, 1971 to keep anappropriate slack in the seat belt applied around the users body. Theseat belt comprises a buckle including one buckle member movable on the[52] U.S. 340/52 E, 307/10 SB, 180/82 C 2 51 9 vehicle body and normallybiased to assume an ex- 0 SB. 186/82 tended position. The buckle memberis temporarily retracted to lockthe belt winder under the engaging pres-References Cited sure of the other buckle member secured to the free endof the seat belt when the belt is'buckled up. UNITED STATES PATENTS3,717,2l6 2/1973 Rothschild 180/82 C 10 Claims, 6 Drawing FiguresPATENIE JULBI ma SHEET 1 OF 3 PATENIEDJULBIIQH 0 3750.102

SHEET 3 BF 3 FIG. 5

SELF-RETRACTING TYPE SEAT BELT DEVICE FOR VEHICLE USE BACKGROUND a.Field of the Invention The present invention relates to seat beltdevices for use in automobiles, trucks and the like vehicles and moreparticularly to those of the self-retracting type including a beltwinder operable under spring bias to wind up the seat belt for thepurposes of facilitating its application around the driver or passengerand preventing it from lying idle on the seat when not used.

b. Prior Art In known seat belt devices of the type described, however,the seat belt in use is at all times kept under an appreciable tensionto press against the users body and thus gives considerable discomfort.

SUMMARY OF THE INVENTION Accordingly, the present invention has for itsobject the provision of a new and improved self-retracting type seatbelt device which can be used at all times keeping an appropriate slackin the seat belt and thus without giving any discomfort to the user.

The seat belt device of the present invention is characterized in thatit comprises buckle means including a first buckle member secured to thefree end of the seat belt and a second buckle member arranged for backand forth movement over a predetermined distance relative to theassociated portion of the vehicle body and biased to normally assume theforwardly extended position, the second buckle member being retractableunder the pressure of the first buckle member to lock the spring-biasedbelt winder of the device when the first buckle member is engaged withthe second buckle member in order to buckle up the seat belt previouslypulled out around the users body and restorable subsequently whenreleased, to said extended position to slacken the seat belt.

The construction of the seat belt device of the present invention willnext be described in detail with reference to the accompanying drawings,which illustrates one preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary cross-sectionalelevation view of the buckle structure of the seat belt device embodyingthe present invention, showing the structure in a disengaged state;

FIG. 2 is a partly schematic elevational view of the belt winder andassociated portion of the device;

FIG. 3 is an elevational view similar to FIG. 1, showing the bucklestructure in a position just engaged and temporarily displaced towardthe associated portion of the vehicle body;

FIG. 4 is a view similar to FIG. 2, showing the winder portion of thedevice in the state corresponding to the buckle state shown in FIG. 3;

FIG. 5 is a view similar to FIGS. 1 and 3, showing the buckle in thestate assumed after the seat belt has been completely applied; and

FIG. 6 is a view similar to FIGS. 1, 3 and 5, showing the bucklestructure unlocked by a push button means.

DETAILED DESCRIPTION Referring to the drawings and particularly to FIGS.1 and 2, reference numeral 1 indicates a seat belt anchored at one endto an automatic belt winder 2; numeral 3 indicates one buckle member ofplug form secured to the free end of the seat belt 1; and numeral 4indicates the other buckle member of a socket form, associated with thevehicle body. A pawled locking lever 5 is pivotally mounted in thesocket member 4 and is normally biased downward by a spring 29. Thesocket member 4 also carries a push button 7 pivotally secured to thepawled lever 5 by a link 8. When the seat belt 1 is pulled out of thewinder 2 and the buckle plug member 3 secured to the belt end isinserted into the opening 41 formed in the socket member 4, the pawledlever 5 operates to engage the plug 3 by entering a recess 6 in the plug3 under the bias of spring 29. Upon depression of push button 7, thepawled lever 5 is moved by link 8 out of engagement with the plug 3 toallow the seat belt 1 to be automatically wound up. Such constructionand operation of the device is generally similar to that of conventionalself-retracting type seat belt devices.

The buckle structure of the device of the present invention furtherincludes a fixed tube 9 secured to the vehicle body 10 by a bracket 11and a movable tube 12 slidably fitted over the fixed tube 9.

The buckle socket member 4 is fixedly fitted to the .free end of themovable tube 12, as shown. Reference numerals 13 and 14 respectivelydesignate an axially extending slot formed in the wall of the fixed tube9 and a limit stop pin secured in the wall of the movable tube 12 andslidably fitted in the slot 13 to serve the purpose a of defining therange-of sliding movement of the movable tube 12 relative to the fixedtube 9. A coiled compression spring 15 is mounted inside the fixed tube9 and is anchored at its opposite ends to the fixed and movble tubes 9and 12 to normally hold the movable tube 12 in extended position.Reference numeral 16 indicates a spring seat secured to the inside ofthe movable tube 12 to receive the adjacent end of coiled spring 15. I

Arranged axially in the fixed tube 9 is a winder locking rod 17 which isnormally urged toward the plugreceiving end 41 of the socket 4 by a coilspring 30, which is weaker than the spring 15. I

A wire 18 is anchored at one end to the locking rod 17 through theintermediary of a slotted connecting tube 21, which is slidably fittedover the locking rod 17 and has an axially extending slot to receivea'limit stop pin 22 secured to the locking rod 17 adjacent to the innerend thereof. The wire 18 is coupled at its other end to a winder lockingpawl 19 (in a manner to be described later) for the purpose oftransmitting movement of the locking rod 17 to the pawl 19.

The locking pawl 19 is in the form of a bell crank lever and is normallybiassed by a tension spring 23 in a direction to engage a ratchet wheel24 integrally secured to the belt winder 2. When the seat belt is not inuse pawl 19 is held outof engagement with the ratchet wheel 24 under thebias of spring 15 acting through the locking rod 17, connecting tube 21,wire 18 and a dog 25 secured to wire 18 for seating engagement with thelocking pawl 19, as seen in FIGS. 1 and 2. Reference numeral 26indicates a safety hook for holding the locking pawl 19 in itsdisengaged position; numeral 27 indicates a dog secured to the wire 18to serve the purpose of moving the safety hook 26 into and out ofengagement with the locking pawl 19; numeral 28 indicates a springnormally biasing the safety hook 26 in a direction to engage the lockingpawl 19; numeral 31 indicates an electric circuit for signalling thedriver that the seat belt is not in use. The circuit 31 includes anelectric power source 32, a warning lamp 33 and switches 34, 35 and 36connected in the circuit in series with each other.

In this circuit arrangement, one of the switches therein, for example,switch 34 is arranged so as to be closed automatically when the driveris seated and another switch 35 is associated with the engine ignitionswitch (not shown) so as to be closed simultaneously therewith.Accordingly, the warning lamp 33 is lighted upon turning of the ignitionswitch to advise the driver to apply the seat belt around his body, theremaining switch 36 being normally held closed under the pressure of thewinder locking pawl 19, as shown in FIG. 2.

In applying the seat belt 1 around his body, the driver pulls out, theseat belt and inserts the buckle plug 3 into the socket 4, thereby toforce the movable tube 12 inwardly against the bias of the coiledsprings 30 and 15 until the stop pin 14 reaches the inner end of theaxially extending slot 13 in the fixed tube 9, as shown in FIG. 3. Onthis occasion, the winder locking rod 17 is retracted i.e., forcedinwardly under the pressure of plug 3, and the stop pin 22 is displacedto the inner end of the slot 20 in the connecting tube 21 therebyforcing the tube 21 to move inwardly. As a result, wire 18 extendingfrom the tube 21 is moved longitudinally to the left as viewed in thedrawings. Incidentally, in case the spring 29 biasing the buckle-lockinglever 5 is stronger than the springs 30 and 15, the buckle plug andsocket members 3 and 4 are engageable with each other only after themovable tube 12 has been fully pushed in.

As seen clearly in FIG. 4, the leftward movement of the wire 18 causesthe safety hook 26 to turn clockwise under the pressureof dog 27, whichis secured to the wire, and thus the locking pawl 19 is released andbrought into engagement with the ratchet wheel 24 under the tension ofspring 23 thereby to lock the automatic belt winder 2 against rotation.At the same time, the switch 36, previously held closed by the lockingpawl 19, is released and opens, and the warning lamp 33 is extinguished.

Subsequently, when the drivers hands are removed from the buckle 3-4,the movable tube 12 is extended under the bias of spring until the stoppin 14 reaches the forward or outer end of the slot 13, as shown in FIG.5, and thus the seat belt 1 is given a slack corresponding to the lengthof slot 13. The slot 13 and pin 14 thus serve as a lost motion means toslacken the seat belt after the buckles 3, 4 have been engaged togetherand subsequently released from manual engagement. Though such restoringmovement of the movable tube 12 naturally allows the locking rod 17 tomove together therewith, the locking rod 17 cannot reach its originalposition as it is restrained by the plug 3, which is in pressure contactwith the outer face 17, of the locking rod 17, and the pin 22 carriedthereon cannot reach the outer end of the slot formed in the connectingtube 21. It is to be noted that such limited movement of the locking rod17, exerts no pulling effect upon thewire 18 but merely allows it to beslightly moved back by the safety hook 26 through the dog 27 secured tothe wire as the safety hook 26 rocks to engage the locking pawl 19 underthe bias of the spring 28, as shown by the dotted lines in FIG. 4.

When the push button 7 is depressed by the driver for disconnecting thesafety belt, the buckle 3-4 is unlocked as described hereinbefore,allowing the locking rod 17 to return to its original position under thebias of spring 30. This causes the stop pin 22 secured to the lockingrod 17 to engage the forward-or outer end wall of the slot 20, as shownin FIG. 6, and to pull back the wire 18. In this manner, the dog 25secured to the wire is brought into engagement with the locking pawl 19to turn the latter out of engagement with the ratchet wheel 24 and thusthe belt winder 2 is released to wind up the now unbuckled seat belt 1.

It will be apparent from the foregoing description that there isprovided a self-retracting type seat belt device wherein when bucklingthe seat belt, or after it has been applied around the user's body, thebuckle is manually pushed in thereby to pull out the seat belt a predevtermined additional length, the belt winder is automatically locked andthe seat belt obtains an appropriate amount of slack when the buckle isreleased and returns to its previous position. It will readily beappreciated that such device can be used with ease and comfort since theapplied seat belt imparts no pressure to the user's body despite theself-retracting nature of the device and thus is highly advantageous foruse in automobiles, trucks and the like.

While one preferred embodiment of the invention has been shown anddescribed, it will be apparent to those skilled in the art that variouschanges and modifications may be made therein without departing from thespirit and scope of the claimed invention.

What is claimed is:

1. A seat belt device for vehicle use comprising a seat belt, a beltwinder connected to said seat belt to urge the belt to retractedposition, buckle means including a first buckle member secured to a freeend of the seat belt, and a second buckle member engageable with thefirst buckle member and supported from the vehicle for back and forthmovement over a predetermined distance, spring means acting on thesecond buckle member to urge the same to a forwardly extended position,the second buckle member being retractable against the opposition of thespring means under the pressure of the first buckle member when thebuckle members are engaged, locking means coupled to the second bucklemember to lock the belt winder when the first buckle member is engagedwith the second buckle member and the seat belt has been previouslypulled out around the users body, said second buckle member includinglost motion means for slackening the seat belt after the buckle membershave been engaged and subsequently released from manual engagement.

' 2. A seat belt device as claimed in claim 1 comprising an electricalcircuit including a signal means for indicating lack of engagement ofthe buckle members.

3. A seat belt device as claimed in claim 2 comprising means connectedto said second buckle member for opening said circuit when said bucklemembers have been engaged together. I

4. A seat belt device as claimed in claim 1 wherein said second bucklemember comprises a tubular member, and means within said tubular membercoupled to said locking means for operating the latter when the bucklemembers are engaged and the second buckle member is retracted under thepressure of the first buckle member.

5. A seat belt device as claimed in claim 4 wherein said lost motionmeans comprises a pin and slot connection between the tubular memberandthe vehicle.

6. A seat belt device as claimed in claim 4 wherein said means foroperating said locking means comprises a displaceable rod, a tube withinsaid tubular member and slidably receiving said rod, said tube and rodhaving a pin and slot connection, and means operatively connecting thelocking means and tube.

7. A seat belt device as claimed in claim 6 wherein said locking meanscomprises a pivotally mounted pawl lever, said belt winder including aratchet wheel facing said pawl lever to be locked thereby when thebuckle members are engaged and the second buckle member is retracted.

8. A seat belt device as claimed in claim 7 comprising means for lockingsaid pawl lever in disengaged position from said ratchet wheel, andmeans for releasing the pawl lever when the buckle members are engagedand the second buckle member is retracted.

9. Aseat belt device as claimed in claim 7 comprising releasable lockingmeans between said buckle members.

l0. A seat belt device as claimed in claim 7 comprising an electricalcircuit including a signal means for indiating lack of engagement of thebuckle members, said circuit including a switch means facing said pawllever for being opened when the pawl lever is engaged with the ratchetwheel and closed when the pawl lever is disengaged from the ratchetwheel.

l l l l l

1. A seat belt device for vehicle use comprising a seat belt, a beltwinder connected to said seat belt to urge the belt to retractedposition, buckle means including a first buckle member secured to a freeend of the seat belt, and a second buckle member engageable with thefirst buckle member and supported from the vehicle for back and forthmovement over a predetermined distance, spring means acting on thesecond buckle member to urge the same to a forwardly extended position,the second buckle member being retractable against the opposition of thespring means under the pressure of the first buckle member when thebuckle members are engaged, locking means coupled to the second bucklemember to lock the belt winder when the first buckle member is engagedwith the second buckle member and the seat belt has been previouslypulled out around the user''s body, said second buckle member includinglost motion means for slackening the seat belt after the buckle membershave been engaged and subsequently released from manual engagement.
 2. Aseat belt device as claimed in claim 1 comprising an electrical circuitincluding a signal means for indicating lack of engagement of the bucklemembers.
 3. A seat belt device as claimed in claim 2 comprising meansconnected to said second buckle member for opening said circuit whensaid buckle members have been engaged together.
 4. A seat belt device asclaimed in claim 1 wherein said second buckle member comprises a tubularmember, and means within said tubular member coupled to said lockingmeans for operating the latter when the buckle members are engaged andthe second buckle member is retracted under the pressure of the firstbuckle member.
 5. A seat belt device as claimed in claim 4 wherein saidlost motion means comprises a pin and slot connection between thetubular member and the vehicle.
 6. A seat belt device as claimed inclaim 4 wherein said means for operating said locking means comprises adisplaceable rod, a tube within said tubular member and slidablyreceiving said rod, said tube and rod having a pin and slot connection,and means operatively connecting the locking means and tube.
 7. A seatbelt device as claimed in claim 6 wherein said locking means comprises apivotally mounted pawl lever, said belt winder including a ratchet wheelfacing said pawl lever to be locked thereby when the buckle members areengaged and the second buckle member is retracted.
 8. A seat belt deviceas claimed in claim 7 comprising means for locking said pawl lever indisengaged position from said ratchet wheel, and means for releasing thepawl lever when the buckle members are engaged and the second bucklemember is retracted.
 9. A seat belt device as claimed in claim 7comprising releasable locking means between said buckle members.
 10. Aseat belt device as claimed in claim 7 comprising an electrical circuitincluding a signal means for indiating lack of engagement of the bucklemembers, said circuit including a switch means facing said pawl leverfor being opened when the pawl lever is engaged with the ratchet wheeland closed when the pawl lever is disengaged from the ratchet wheel.